1. Field of the Invention
The present invention is directed to the field of high voltage commutation distributors for use within internal combustion engines, and more specifically, to a light weight distributor rotor driveshaft.
2. Description of the Prior Art
Electrical commutators for internal combustion engines are commonly called distributors and normally include a base which is attached to the engine and houses a shaft. The shaft is gear driven by the engine to rotate in synchronization with the engine. A rotor element is attached to the shaft inside a commutation cavity defined by the distributor base and cap. A distributor cap is formed to mount on the base and contains several electrical contacts that are insulated from each other and connected to individual spark plugs of the engine. The rotor element may contain one or more commutation electrodes that provide electrical connection between a common high energy voltage source electrode and individual ones of the spark plug contacts on the cap.
Traditionally, driveshafts which connect between the engine synchronization gear and the rotor element inside the commutation cavity were formed of metal in order to guarantee long life in severe temperature environments. The conventional metal shafts are usually ball bearing or bushing mounted to provide low friction rotation. Such conventional shafts and mounting techniques are shown in U.S. Pat. No. 4,011,476; No. 3,989,023; No. 3,799,135; No. 3,660,626; No. 3,646,922 and No. 3,258,551. Although the conventional metallic rotor shafts are desirable in that they are easily lubricated and are able to withstand the severe temperature variations of the automotive environment, they have the disadvantages of requiring highly accurate machining and skillful assembly while at the same time, due to their mass, contribute a weight disadvantage to the associated vehicle.